Oxidative damage has been implicated in the pathology of several diseases, but only recently has it been suggested to have a role in adverse reproductive conditions. Many environmental and occupational exposures are known pro-oxidants (e.g., many solvents and metals), and they may adversely affect reproduction by causing oxidative damage. This research project explores the relationship between environmental exposures, oxidative stress, and adverse reproductive conditions. We working with two major aims. First is the continued analysis of small samples of existing data concerning levels of metals and other industrial pollutants, markers of oxidative damage, and reproductive outcome in pregnant women and maternal-infant pairs living in the vicinity of industrial enterprises in various areas of Bulgaria. This year we have completed analysis of data from an area polluted by chemical plant emissions. The second aim of the Bulgarian work is to conduct a pilot study that will resolve the amount of variability in the markers of anti- oxidant and oxidant status due to seasonal and intra-individual variation and to storage procedures. Twenty non-pregnant women have given serial blood samples; the results indicated that the samples could not be stored at all for more than a few hours without altering the level of glutathione and lipid peroxides significantly. The level of intra- individual variability is being established. Also, 20 pregnant women to date have been enrolled at booking and are being observed for changes in biomarkers as pregnancy progresses. A secondary activity in the pilot study is to analyze dietary data from pregnant women to determine the relationship of oxidative status markers and dietary intake of anti- oxidants.